Displacement pump



Feb. 11, 1936. R. R. WIGHT 2,030,827

DISPLACEMENT PUMP Filed Jan. 2, 1955 ,e 19.14 71) l NVENT my 'AITORNEY Patented Feb. 11, 1936 PATENT OFFICE DISPLACEMENT PUMP Roy R. Wight, Wichita. Falls, Tcx., assignor to The Texas Company, New York, N. Y., a cornotation of Delaware Application January 2, 1935, Serial No. 20

8 Claims. (01. 103-234) This invention relates to new and useful improvements in displacement pumps.

The object of this invention is to obtain a simple compact displacement pump which will be entirely automatic in its operation after it is once adjusted.

A further object of this invention is the construction of a displacement pump for intermittent operation in gas lift oil wells which will be controlled by the static pressure of oil in the well.

Another object of this invention is the construction of a displacement pump which will be economical in its operation and which when used in gas lift oil wells will use a minimum of gas in raising the oil. A

In carrying out this invention an eduction tube is suspended inside the well casing and a piston chamber is secured to the lower end of the eduction tube. A piston operating in this chamber is normally maintained in a predetermined position by mechanical means or by low pressure gas or other fluid but will be moved from this position by the weight of the column of oil in the eduction tube when this column reaches a predetermined height. The piston is attached to a sleeve valve which in turn controls the admission to the well of the high pressure gas or other fluid which is used to carry the oil to the surface. Thus, with the piston in its normal position the high pressure gas ports are maintained in a closed position but when the oil seeping into the eduction tube has reached a predetermined height the piston is carried-out of its normal position and high pressure gas admitted to the tubing carries the column of oil in the eduction tube to the surface.

The pump forming the subject of this application is, of course, not applicable to oil well use only but may be used wherever a displacement pump is suitable for the work in hand.

The invention will be more readily understood fro-ma reading of the following specification and by reference .to the accompanying drawing in which an exampleof the invention 'is shown and described. v t

Figure 1 is a vertical sectional view of a displacementpump, constructed in accordance with my invention, in which-the'pi'stbn is maintained in its. normal gpositionflby lo'f-wjpressure gas supplied thrda small string or tubinggj I of the piston from string of tubingsurrounding the eduction tube.

displacementpu np infwh ich Figure 3 shows a displacement pump in which the piston is maintained in its normal position by a spring or other mechanical means.

The same numerical designation for corresponding parts is used throughout the speclfica- 5 tion and the drawing.

In Figure 1 the numeral l0 designates the well casing. The eduction tube H is suspended from the surface inside of the casing and a cylindrical chamber I2 is securely threaded'to the lower end 10 of the eduction tube and is supported thereby.

This chamber is designed to carry a packer I3 which engages the outer chamber wall and the inner casing wall and effectively cuts ofi the well from the upper part of the casing.

The base of the chamber is also threaded and carries a section of pipe ll which has perforations l5 thru which the oil in the well may enter.

The interior of the cylindrical chamber adcommodates a piston l6 which is formed integral 20 with or may be attached to a tubular sleeve valve I! which controlsthe high pressure gas ports IS in the eduction tube. This sleeve valve carries a check valve H! at its lower'extremity and contains ports 20 opening into the upper "piston 25 chamber 2|.

Near the base of the lower piston chamber 22 an opening 23 is formed into which a pipe 24 is threaded, thru which low pressure gas may be passed to the lower piston chamber.

In order that the oil and gas in the well will not seep into chamber 22 a packing ring 25 may be placed between the inner wall of the base 01' the cylindrical chamber and the exterior of the sleeve valve. This packing may be held in place 35 by a collar 26 or by some other suitable means.

Figure 2 illustrates a modification of Figure 1 in which the low pressure gas is passed to the lower piston chamber, not by a small pipe 21 but thru a pipe 21 which surrounds the eduction 40 tube and which is securely threaded to a flange on the piston chamber. From tube 21 the low pressuregas is passed to the lower piston chamber 22' thru a passage 28 in the wall of. the piston chamber. The'Thigh pressure ports IS in the eduction tube and 29 .in the tube surrounding it are connected in this instance by small pipes 30.

As' indic'ated in Figure 2, packing l3 may be supported 'fromthe "wall. of the tube suspended from-the-piston chamber instead of from the walls of the pistonchamber. l l

Figure 3 corresponds almost -exa'ctlywith Fig-- ure 1 except that a spring 3| of predetermined pressure value is placed in the lower piston cham- 5 ber 22 and, there is, therefore, no low pressure.

Under normal conditions a gas of a prede-' termined low pressure is constantly fed from the surface thru tube 24 and inlet 23 into the lower piston chamber 22 and this gas acting on the underside of piston l6 maintains the sleeve valve in a position such that inlet ports l8 are closed.

Theoil in the eduction tube and sleeve valve is, however, permitted to pass thru ports 20 into the upper piston chamber 2| and so exerts pressure on the upper surface of piston l6.

; When the oil in the eduction tube has risen to a predetermined height the static pressure of this column will move the piston in a downwardly direction against the force of the low pressure gas andports l8 will be opened as the sleeve valve is moved in a downwardly direction.

High pressure gas is at all times being forced from the surface into the area between the casing I0 and eduction tube H and as soon as ports l8 are opened the gas blows into the eduction tube and raises the column of oil to the surface.

While the pressure within the education tube is temporarily raised by the high pressure gas it again drops as the oil is forced out of the tubing at the surface and as the static pressure on top of the piston is decreased the low pressure gas ex- 75 tube e'rts sufficient force to push the piston up andthe' sure gas, and once the desired pressure on the.

underside of the piston has been determined and the flowof low pressure gas regulated accordingly, the pump becomes automatic and requires no further attention.

The details of the surface equipment do not form a part of this invention and will consequently not be described; It will, however, be obvious, for instance, that there must be a relief valve on the low pressure gas line to take care of the compression of this gas on the down stroke of the piston.

The operation of the pump illustrated in Figure 2 isv identical with-thatshown in Figure 1. The low pressure gas, as previously pointed out, being passed to the lower piston chamber 22 thru the space between eduction pipe II and the second string of tubing 21 and from there thru passage 28 to chamber 22.

The operation of the pump shown in Figure 3 differs from the other two pumps in that the a piston is maintainedin its normal position by mechanical means rather than by low pressure gas. While a simple coil spring has been illustrated, other suitable mechanical means may obviously be substituted therefor. In this connection, it is to be noted that the selected mechanical means must have a predetermined pressure value so that a column of oil of the desired height will effectively depress the piston and allow the high pressure gas to enter the educ i n .2,oso,s27

It will be seen from the foregoing description that the construction of this pump is extremely simple and compact and that there is little or nothing to get out of order.

It will also appear that there is little loss in low pressure gas and a. minimum loss of high pressure gas for when sufficient gas has been admitted to the eduction tube to carry the, oil to the surface the high pressure gas supply is cut oil.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made, without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims. i

I claim:

1; In a displacement pump an outer casing, a centrally disposed tube, a port located in said tube, a cylindrical chamber connected with said tube, a piston adapted to operate in said cham; ber, means. controlled by the piston for controlling said port, an aperture in said control means giving access to the upper surface of the piston, means for maintaining a predetermined pressure on the lower surface of the piston and a check valve, seated in the lower end of said control means.

2. The combination with a well casing of a packer engaging the outer walls of said chamber and the casing wall, a piston in the form of a hollow cylinder located in said chamber, a cylindrical sleeve secured to the inner'surface of said piston and adapted to control the port in said first tube, an aperture in said sleeve giving ac cess to the upper surface of the piston, a second tube disposed between the first tube and the easing and leading into the lowest portion of the piston chamber.

3. The combination with a well casing of a centrally disposed tube, a port located in said tube, a chamber suspended from said tube, a packer engaging the outer wallof said chamber and the casing wall, a pistonin the form of a hollow cylinder located in said chamber, a cylindrical sleeve secured to the inner-"surface ofsaid piston and adapted to control the port in said first tube, an aperture in said sleeve giving access to the upper surface of said piston and mechanical means for maintaining the piston in a predeter mined normal position.

4. The combination with a well casing of two tubes disposed one within the other, a tubularton chamber and a packer engaging tthe outer wall of said last mentioned tube and the casing wall. a

I 5. In a well pumping apparatus operated by the displacement of liquid by fluid under pressure a casing, a. centrally disposed eduction hibe having gas ports'located in its walls adjacent to its lower ends, a piston chamber suspended'from said eduction tube and having p nings at both chamber and the inner casing wall and adapted to prevent high pressure gas from passing from the space between the casing and eduction tube into the well, a piston in the form of a hollow cylinder adapted to operate in said chamber, a cylindrical sleeve of greater length than the piston chamber secured to the inner surface of said piston and extending thru the opening in the piston chamber and adapted to close the gas ports in the eduction tube when the piston is in its upper position, a check valve located in the lower end of said sleeve adapted to' permit the liquid being pumped to flow into the sleeve, apertures in the sleeve adapted to admit such liquids to the upper surface of the piston, a second tube disposed between the casing and the eduction tube and connected with the piston chamber which is adapted to admit low pressure gas to the lower surface of the piston.

6. In a well pumping apparatus operated by the displacement of liquid by fluid under pressure a casing, a centrally disposed eduction tube having gas ports located in its walls adjacent to its lower ends, a piston chamber suspended from said eduction tube and having openings at both ends, a packer engaging the outer wall of said chamber and the inner casing wall and adapted to prevent high pressure gas from passing from the space between the casing and eduction tube into the well, a piston in the form ota hollow cylinder adapted to operate in said chamber, a cylindrical sleeve of greater length than the piston chamber secured to the inner surface of said piston and extending thru the opening in the piston chamber and adapted to close the gas ports in the eduction tube when the piston is in its upper position, a check valve located in the lower end of said'sleeve adapted to permit the liquid being pumped to flow into the sleeve, apertures in the sleeve adapted to admit such liquids to the upper surface of the piston, a spring mounted in the piston chamber below the piston adapted to maintain the piston in a predetermined normal position.

'7. In a pumping apparatus operated by the displacement of liquid by fluid under pressure an eduction tube, a port in said eduction tube adapted to admit high pressure fluid into the eduction tube, a sleeve valve adapted to control the said port, a piston adapted to control said sleeve valve, means for admitting the liquid to be pumped to the upper surface of the piston, a low pressure fluid source and means for applying such fluid to the lower surface of the piston to maintain the piston in a predetermined normal position.

8. In a well pumping apparatus operated by the displacement of liquid by fluid under pressure a casing, an outer tube disposed within the casing, an eduction tube disposed within said outer tube, a tubular port connecting the space between the casing. and the outer tube with the interior of the eduction tube, a piston chamber suspended from said tubes and having openings at both ends, a piston in the form of a hollow cylinder adapted to operate in said chamber, a cylindrical sleeve of greater length than the piston chamber secured to the inner surface of said piston and extending thru the openings in the piston chamber and adapted toclose'the port in the eduction tube when the piston is in its upper position, a check valve mounted in the lower end 01' said sleeve adapted to admit the liquid being pumped into the sleeve, apertures in the sleeve adapted to admit such liquid to the upper surfaceof the piston, a passage in the piston chamber wall connecting the area between said outer tube and the eduction tube with the lowest portion of the piston chamber, a perforated tube suspended from said piston chamber and a packer engaging the outer wall of said last mentioned tube and the casing wall to prevent high pressure gas from passing from the space between the casing and the centrally disposed tubing into the well.

ROY R. WIGHT. 

